Vehicle-motor-control system.



PATENTED NOV. 12, 1907.

W. COOPER.

VEHICLE MOTOR CONTROL SYSTEM.

APPLIOATION FILED JAN. 3. 1906.

2 HEBTS-SHEET 1.

ATTORNEY WITNESSES:

PATENTED NOV. 12, 1907.

W. COOPER.

VEHICLE MOTOR CONTROL SYSTEM.

APPLIOATION FILED JAN. 3. 1906.

2 SHEETS-SHEET 2.

INVENTOR ATTORN EY UNITED STATES PATENT OFFICE.

I WILLIAM COOPER, OF WILKINSBI'RG, PENNSYLVANIA. ASSIGXOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY. A CORPORATION OF PENNSYLVANIA.

VEHICLE-MOTOR-CONTROL SYSTEM.

Specification of Letters Patent.

Patented Nov. 12, 1907.

Application filed January 3- 1906. Serial No- 294.422.

To all uimm it may concrrn:

Be it known that I. \YILLiAu CooPEn. a citizen of the United States. and a resident of \Yilkinsburg, in the county of Alleghciiy and State of Pennsylvania, have invented-a new and useful Improvement in Vehicle- ItIotor-Control Systems. of which the following is a specification.

.\iy invention relates to vehicles. and has special reference to the starting of'such vehicles as are electrically propelled and are adapted for railway service.

The object of my invention is to provide means for so regulating the torque applied to the several pairs of vehicle wheels that a maximum accelerating force is insured.

In the design and construction of vehicles which are propelled by motors or similar driving means carried upon the vehicle itself. the entire weight of the vehicle and its equipment is. so far as possible, equally distributed upon the several pairs of driving wheels. This is substantially true of vehicles which are driven by electric motors and, when starting such vehicles, it has been customary in the prior art to connect the motors, which were usually of the series type and of similar design, in series circuit relation so that equal torques were exerted by the several motors. This is evident from thefact that. the torque exerted by an electric motor is dependent upon and proportional to. the armature current. the magnetic lines produced by the field magnet winding and the number of armature convolutions: these factois being equal in the several motors on account of the similarity of design and the series circuitrelations existing between them.

When electric vehicles constructed along the lines indicated above are started under adverse or heavy conditions of service, such as are constantly imposed upon motor-driven locomotives, the forward wheels on each truck are observed to slip before the rear wheels of the same truck, which proves that at the moment of starting, the weight of a vehicle is unequally dis tributed between the forward and rear wheels of each truck although such weight may be equally divided whenthe vehicle is at rest. This action may be explained as: due to the reaction of the rails upon the wheels when a rotary motion is imparted to the latter.

The draw-bar pull of a locomotive or the accelerating force ofa vehicle similarly propelled, is therefore proportional to a. multiple (depending upon the number of motois).of the maximum value of torque which may be applied to the forward wheels of any one truck without slipping, since. the torques exerted by the several motors are equal, and this value is substantially less than it may become if the torque of each motor is automatically varied, with respect to that of the others, to suit the specific conditions imposed upon it at starting.

With a view to increasing to a maximum the drawbar pull which may be exerted by a locomotive of a. given weight. I have provided means for automatically reducing the relative torques exerted by the forward motors of each truck and since the possibility of slipping exists only during the starting period, I automatically reestablish the equality between the torques exerted by the several motors when their circuit connections are changed to a multiple relation. This object may be most conveniently and economically accomplished by varying the field magnetization on the forward motors of each truck since the other factors upon which the torque depends do not lend themselves readily to automatic adjustment. To effect this variation I provide a shunt circuit for the field magnet winding of each motor which includes a suitable resistance and a circuit interrupting device. circuits for the forward motors of each equipment are closed when the vehicle is started, their selection being dependent upon the reversing switch of the motor control system which determines the direction in which the motors are started. In this way the ope ator who determines the direction of travel, simultaneously shunts the field windings of the forward motors for that direction on each truck which reduces the field excitation of the motors affected and consequently the torque which they exert and thereby makes it possible for a larger current to be applied to all the motors without causing any of the wheels to slip.

' I have found by practical tests that in some instances the torque exerted by the rear motors may be from 40 to percent. greater than that exerted by the forward motors on a given truck before slipping occurs, so that,

.in a four motor equipment, the draw-bar pull may be increased from20 to 25 percent.

Figure 1 of the accompanying drawings is 2, diagrammatic view of the circuit connections for a group of four electric motors which embody my invention and which are, for simplicity and convenience, controlled by a system comprising a plurality of independent electrically-operated switches all of which govern the motor circuits directly and are controlled by a master switch. Fig. 2 is an elevation of a double truck vehicle running gear which shows the location of the motors of Fig. l on the trucks, Fig. 3 is 2. diagrammatic view of the circuit connections for a group The shunt of two electricrnotors that are controlled directly-by a drum type of controller, the cylindrical drums of Which are shown as developed into a single plane and Fig. 4 is an elevation of, a single truck vehicle running. gear which shows the location of'the motors of Fig. 3. The system'of. 3 is also arranged in' accordance with my inventionbut in this case 'a single resistance is used for shunting both of the motor field magnet windings by transferring it from one to the other accord-.-

. magnet windings o, 6, 7 and S, the motors 1*? and 2 being located on a truck 5 while motors a and 4 are located on a truck 6. The circuit arrangement of these motors is dependent upon a master switch or controller 9 which is adapted to occupy any one of a plurality of 7 7 f) 7 7 7 7 P: q7

s and t and which controls directly a plurality of electrically operated switches. When the controller 9 occupies the position 11 energy is supplied from the positive terminal of a battery .10 through contact finger 1'1, and contact ring segment 12 to contact fingers 13, 14 and 15. From contact finger 13 energy is supplied tofa magnetizingcoil l6 ofa line switch 17 from which point circuit is completed through a conductor 18 to the negative terminal of the battery 10;

from finger 14 energy is supplied to magnet windings 18 and 190i switches 20 and 21, the remaining terminals of which are also connected to the conductor 18,.and from the finger 15 energy is supplied to'magnet coil 22 of the switch 23. The ring segment 12 is electrically connected with a ring segment 2 4, which, in this position, is engaged by contact fingers 25 and 26, so that energy is also supplied to magnet coils 27, 28, 29, 30, 31, 32, 33 and 34 from finger 25 and magnet coils 35 and 36 from contact finger 26 the return circuit from all of these coils being completed though the conductor 18. The magnet coils 27 to 36 inclusive are actuating coils for switches 37 to 46 inclusive. When these: switches have been closed by reason of the energizing of their magnet coils, energy is supplied from a line conductor 47 through switches 17 and 37,

armature switch 38,- field magnet winding 5, resist ance 48, switches 20 and 39, armature 2,. switch 46, field magnet winding 6, resistance 49, switches 23 and- 41,. armature 3, switch 42, held magnet winding .7,-

resistance 50, switches 21 and .43, armature 4, switch 44, field magnet winding-8-- and resistance 51 to an.

opposite line conductor 52. Shunt circuits are com pleted around field magnet windings 6'and 8, respec-' tively, through resista'nce53 and switch 45, and resistance 54 and switch 46. I r i It will beobserved that the our motors are-now connected in series relation with resistance'portions 48, .49, 50 and 51 included in the circuit, while a circuit is provided in parallel with the field magnetwindings 6 and 8 of the motors 2 and 4. These multiple circuits carry a portion of the current, all of which would otherwise pass through thefield magnet winding.

As the controller 9 occupies positions b, -c, d and e, consecutively, fingers 63, .64, 6'5 and 66 successively engage ring segment 12, the circuit connections for the motors remaining the same except for the resistance circuited by the switches' 55, 56, 57 and 58, movement of which is effected by their respective magnet coils 59,

may be applied'fails to startwhen the controller has passed through. positions a, b, c and d, and occupies the position e, it: may be assumed that the motors are inadequate for the service imposed. The current in the field magnet windings 6 and 8 of the motors 2 and 4 which are the forwardmotors on the trucks 5? and 6, is reduced through these possible starting positions so duc ed. The contact finger 26 becomes disengaged from the ring segment 24 as the controller 9 moves from the position e to'the position f, since the possibility of the vehicle wheels slipping is removed after the motors are started. The contact fingers 15, 63, 64, and 66 are then disengaged from the ring segment 12 and finger In this way, energy is no longer supplied to the magnet 23, 55, 56,- 57 and 58 are opened and switches 68 and 69 are closed by reason of the. completion of .the battery circuit through magnet coils 70 and 71, which are sup plied with energy from contact finger 67 and are connected to the negative conductor 18. Circuit is now completed from the supply conductor 47 through the 39, armature 2, switch 40, field magnet winding 6, re-

ductor 52, and also through the line switch 17 switches 68 and 41, armature 3, switch '42, field magnet winding 7, resistance 50, switches 21 and 43, armature 4, switch 41, field'magnet winding 8'and resistance 51 to the line conductor. Thus motors 1 and 2 are connected across ,the line in series relation. with suitable resistance in nected in multiple relation with the first two As the controller occupies positions g and h, resistance portions 48 and 50, and resistance portions 49 and 51are, respectively, short-circuited by the reclosure of the with ring segment'24 in position g and the similar en' gagement of fingers 64 and 66in position h. The resistance-short-circuiting switches are again opened as coils l8 and 19 are deenergized and switches 20 and 2-1 'are opened Contact finger 72 moves into engagement with contact ring segment 24-andenergy is supplied therethroughto the magnet coils 73, 74, 75 and 76 of the switches 77,- 78, 79 and 80 which are consequently closed Ci cuit is now completed from line conductor 47 through line switch 17, switch 37, armature ,1, switch 38, field magnet winding 5, resistance 48 and switch 78 to the line conductor 52;from the line switch 17 portions 48, 49, 50 and 51, which are successively short that the torque exerted by these motors is also. re-

67 is moved into engagement with the ring segment 24. I

coils 35, 36, 22, 59, 60, 61 and 62 so that switches 45, 46,

line switch 17, switches 37, armature 1, switch 38,

field magnet winding 5, resistance 48, switches 20 andv circuit and the motors 3 and 4 are similarly conswitches 55 and 57, and 56 and 58, respectively, which is eifected by the reengagement of fingers 63 and 65 60, 61 and Ifthe vehicleto which the four motors s'istance 49 and switch 69 to the opposite line c'on- .the controller moves to position i and finger l4gbecomes disengaged from the ring segment 12 so that the magnet through switches 77 and 39, armature 2, switch 40, field magnet winding 6, resistance 49 and switch 69 to the line conductor; through switches 68 and 41, armature 3, switch 42, field magnet winding 7, resistance 50 and switch 80 to the conductor 52 and through switches 79 and 43, armature 4, switch 41, field magnet winding 8, resistance 51 to conductor 52.

When the controller finally occupies position j, electromagnets 59, 60, 61 and 62 are energized and the switches 55, 56, 57 and 58 are closed so that resistance portions 48, 49, 50 and 51 are short-circuitcd, leaving the four motors connected in multiple relation across the line according to the usual practice. The direction ofrotation of all the motors may be reversed by rotating the controller to the off position and moving it consecutively through positions is to t inclusive, in which positions the engagement of the fingers 11, 13,

. 14, 15, 16, 63, 64, B5, 66, 07 and 72 are the same as already described for the positions a, b, c, d, e,f, g, h, 2' and j. Energy is not supplied, however in these positions to fingers 25 and 26 but energy is correspondingly supplied tocontact fingers 81and 82. From the finger 81 energy is supplied to magnet coils 83, 84, 85, 86, 87, 88,

during thepositions k, l, m, 'n and o to electromagnets 99 and'100 of switches 101 and 102, which are closed duringthese positions to 'form shunt circuits comprising a resistance portion 103 and switch 101, a resistance a 104 and a switch 102, respectively. Inthis way the current passing through thefield magnet windings 5 and7 of the motors 1 and 3* is decreased during the positions is, l, m, n and 0, which is the starting position for this direction of rotation, and thereloy the torque is reduced during the starting period in these two motors which-are now the forward motors on the trucks 5 and 6.

- In the system of Fig. 3 which comprises two motors that are provided with armatures 105 and 106, field magnet windings 107 and 108 and a plurality of resistance, sections 109, 110 and 111, the circuit arrangement of the motors and resistance sections is determined by a controller, thecontrol drum 112 of which is adapted to occupy a plurality of positions a, b, c, d,-e, f, g and h and ,the reverse drum 114 ofwhich is adapted to .oc-.

cupy positions 11 and j. Field magnet windings 107 and 108 maybe shunted by a resistance 113 which is connected in multiple circuit with onefield magnet starting positions a, b, c and d. As the druin 112 occupies successive positions a, b, c and d the resistance portions 109, 110 and 111 are short-circuited in a well known manner, the direction of rotation of the motor being determined by the reverse drum 114. Since the action of controllers of this characters is no part of my present invention I deem it unnecessary to describe the circuit arrangements for the several controller positions in detail.

When the drum 112 occupies position a and the rcversing drum 11.4 occupies position i a shunt circuit is completed from one terminal of the field magnet winding 108 through conductor 115, Contact finger 116, ring segments 117 and 118', contact finger 119, resistance 113, contact finger 1.28, ring segment 121, contact fingers 122 and 123, ring segment 124. contact finger 125 and conductor 126 to the opposite terminal of the field magnet winding. This resistance shunt circuit is maintained as longas the contact fingers 123 and 125 are in engagement with ring segment 124; namely, starting positions.

a.b,candd.

If the reversing switch 114 occupies position 9' a shunt circuit is completed from one terminal of the field magnet winding 107 to conductor 127, contact finger 140, ring segments 129 and 130, contact finger 119, resistance 113, contact finger 128, ring segments 131 and 1.32, contact finger 133, conductor 134, contact finger 135, ring segments 13 6 and 137, contact finger 138 and conductor 139 to the opposite terminal of the field magnet winding. The contact finger 135 is similarly disengaged from the ring segment 136 after the controlling drum has traversed the starting positions a, b, c and d.. In this way, although the resistance 113 is used in 1 both instances, the field magnet windingof the forward motor is shunted for each direction of travel. so that the bar pull or accelerating force of the vehicle is consequently increased, as hereinbefore explained.

When two governing switches such as controller 112,

Fig. 3, are used, one on each end of'a vehicle, the circuit connections for both are similar to those sho'wn in the figure but care should be taken to effect the connection of the resistance 113 in parallel with the field magnet winding of the forward motor for each direction of motion whether the motors are governed from the one or the other of the switches.

I claim as my invention:

1. Ida vehicle, the combination with one or more trucks and means for driving the truck wheels in pairs, of means for decreasing the torque exerted upon the leading pair of wheels of each truck (luring starting.

2. In an e1ectric.vehicle,.the combination with one or more carrying trucks and electric motors for driving the respective pairs of truck wheels, of means for relatively reducing the torque exerted by the forward motor on each truck during starting.

3. In an electric vehicle, the combination with one or. more'ca'rrying trucks and an electric motor for driving each pair of truck wheels, of means for automatically reducing the relative torque exerted .by the forward .motor' o n .je ach truck during starting. '4. The combination with a. plurality of electric vehicle motors, field magnet windings therefor, of means 'for relatively and automatically reducing the magnetization produced by said field magnet windings in the forward mdtor of each truck., 1 :5. The combination withan electric vehicle, two trucksthereforffour similar ui'otors equallydisposed on said fig tucks, of means for relatively, reducingathe torque of the forward motor on each" truck while the motors are conneeted inseries relation.

The combination with an electric vehicle, two trucks therefor, four similar motors equally disposed on said trucks,- of means for relatively and automatically reducing the torque of the forward motor on each truck while the motors-are connected in series relation,

T, The combination with a plurality of electric driving motors equally disposed upon vehicle trucks and control ling means for said motors. of means for relatively and automatically decreasingthe field magnetization of the forward motor on each truck.

8 The combination with a plurality of electric driving motors equally disposed upon vehicle trucks and controlling means for said motorsof means for relatively and automatially decreasing the field magnetization of the forward motor on each truck while the motors are connected in series relation.

9. The combination with four electric driving motors equally disposed on two vehicle trucks and controlling means for said motors, of means for automatically completing a resistance circuit in parallel with the field magnet winding of the forward motor on each truck. 10. In an electric vehicle, the combination with one or more trucks and an electric driving motor for each pair of wheels, of means for relatively and automatically reducing the torque of the forward motor on each truck during the starting period that is dependent upon a reduction of the magnetizing current in the field magnet circuits of said forward motors.

11. In an electric vehicle. the combination with a plurality of electric motors. field magnet windings therefor and-contizolling'means which-determine the motor circuit relations. of means for relatively reducing the torque exerted by the forward motor on each vehicle truck during the starting period.

- 12. In an electric vehicle. the combination with a plurality of electric motors, field magnet windings therefor and controlling means which determine the motor circuit relations. of means for relatively reducing the current .flowing through the field magnet windings of the forward motor on each truck during the starting period.

13. In an electric vehicle, the combination with a plurality of electric motors. field magnet windings therefor and controlling means which determine the motor circuit relations, of a plurality of resistance shunt circuits for the several field magnet windings in which interrupting devices are located and means for closing the shunt clrcuit for the forward motor on each vehicle truck.

I-l. The combination with a vehicle truck, a pair of drivingmotors located thereon, field magnet windings therefor and means for determining the direction of the motion imparted to the truck. of means for automatically transferring a shunt resistane from the field magnet winding of one motor to the field magnet winding of the other motor when the direction of truck motion is reversed.

1-5. In anelectric vehicle, the combination with one -or more trucks. a plurality of electric motors equally distributed thereon.' field magnet windings for the several motors and means for controlling the motor circuit arrangement that comprises a plurality of independent, electrically-operated switches, of means for relatively reducing the torque on the forward motor on each vehicle truck during the starting period.

16. In an electric vehicle, the combination with one or more trucks, a plurality of electric motors equally distributed thereon, field magnetwindings for the several motors and means for controlling the motor circuit arrangement that comprises a plurality of independent, electrically-operated switches, of means for relatively reducing the current flowing through the field magnet windings of the forwardniotor on each truck during the starting period. 17. In an electric vehicle, the combination with one or ing the shunt circuit of the forward motor on each truck.

In testimony whereof, I have hereunto subscribed my name this 30th day'of December, 1905.

WILLIAM COOPER.

Witnesses:

R. J. Dmnnonx, BIBNEY Hm'ns. 

